Fatigue crack is one of the main damages of steel bridges. In general, surface coating cracks in welded joints are removed and magnetic particle test is performed on areas where fatigue cracks are suspected. However, if magnetic particle test is performed on all surface coating cracks, the inspection costs will increase. Therefore, there is a demand for technology that can detect fatigue cracks without removing the surface coatings. In this study, we investigated the eddy current testing to the detection of fatigue cracks in welded joints from surface coatings, and methods to improve the detection performance and accuracy.
